Droplet-based microfluidics is a powerful emerging set of techniques with a great deal of application in chemistry and biology. Droplets can be merged with other droplets, split into multiple droplets, sorted, and/or used to house reactions for example. Droplet-based microfluidic techniques allow for the production and handling of a very high volume of droplets per unit of time. Hence, droplet-based microfluidic devices are an ideal tool for high-throughput applications.
A number of patent applications describe formation and/or use of droplets for these and other procedures. A representative list includes: U.S. patent application Ser. No. 11/246,911, filed Oct. 7, 2005, entitled “Formation and Control of Fluidic Species,” published as U.S. Patent Application Publication No. 2006/0163385 on Jul. 27, 2006; U.S. patent application Ser. No. 11/024,228, filed Dec. 28, 2004, entitled “Method and Apparatus for Fluid Dispersion,” published as U.S. Patent Application Publication No. 2005/0172476 on Aug. 11, 2005; U.S. patent application Ser. No. 11/360,845, filed Feb. 23, 2006, entitled “Electronic Control of Fluidic Species,” published as U.S. Patent Application Publication No. 2007/0003442 on Jan. 4, 2007; International Patent Application No. PCT/US2006/007772, filed Mar. 3, 2006, entitled “Method and Apparatus for Forming Multiple Emulsions,” published as WO 2006/096571 on Sep. 14, 2006; U.S. patent application Ser. No. 11/221,585, filed Sep. 8, 2005, entitled “Microfluidic Manipulation of Fluids and Reactions,” published as U.S. Patent Application Publication No. 2007/0052781 on Mar. 8, 2007; U.S. patent application Ser. No. 11/698,298, filed Jan. 24, 2007, entitled “Fluidic Droplet Coalescence,” published as U.S. Patent Application Publication No. 2007/0195127 on Aug. 23, 2007; and U.S. Provisional Patent Application Ser. No. 60/920,574, filed Mar. 28, 2007, entitled “Multiple Emulsions and Techniques for Formation,” each incorporated herein by reference.
Although many advances associated with formation and use of droplets have been achieved, there is a need for improved techniques and tools.